The invention pertains to a method for the timed, stepwise conveyance of piece goods in a filling machine for liquid products along a conveying line with a first and a second section, comprising the steps of                conveying the piece goods in the first section by means of a first conveying means and conveying the piece goods in the second section by means of a second conveying means;        unloading the piece goods from the first conveying means and loading the second conveying means with the piece goods.The invention also pertains to a device for the timed, stepwise conveyance of piece goods in a filling machine for liquid products along at least one conveying line with a first and a second section, comprising a first conveying means with a timed, stepwise drive for conveying the piece goods in the first section and a second conveying means with a timed, stepwise drive for conveying the piece goods in the second section.        
Filling machines for filling packaging containers consisting of composite cardboard material with liquid products, especially liquid food products, are known from the prior art. Concerning the design of such a filling machine, reference can be made by way of example to DE 41 42 167 C2.
In a filling machine, a folded package jacket is picked up in a first section of a conveying line by a first conveying means. The first conveying means is usually configured as a mandrel wheel, rotating in stepwise fashion, which comprises several radially outward-projecting mandrels, which engage in the unfolded package jackets. While the mandrel wheel is in the idle interval of its timing step, an operation is carried out at the free ends of the package jackets. In particular, folding and pressing tools are used to produce the bottom of the package, so that a half-open packaging container is formed from the package jacket. As soon as the mandrel carrying the half-open packaging container is pointing vertically downward, the packaging container is unloaded from the mandrel wheel with the help of a stripper; the container then slides into a cell, oriented to align with the mandrel, of a second conveying means, in particular a conveying means configured as a link-belt conveyor. The packaging container, which is open at the top, stands upright in the cell and is conveyed through a sterile space, for example, of the filling machine, in which a filling station for the liquid products is located. While the second conveying means is in an idle interval of its timing step, another operation is carried out such as, in particular, the filling of the packaging container.
The first and second conveying means are operated with the same timing. The speed of the stepwise movement is based on the most time-consuming work operation to be performed on the conveying line. In the case of the known filling machines, this is the introduction of the liquid product into the packaging container. During this filling operation, the stepwise movement must be slow enough to prevent foam from forming and/or from the acceleration to become too great, since that could cause product which has been introduced into the packaging container to slosh about. In no case may any foam or liquid product spill onto the inside surfaces of the upper edge of the packaging container, because these areas must be kept liquid-free for the sake of the next work step, in which the top of the package is formed; otherwise, a satisfactory seal, produced by the application of heat and pressure, cannot be achieved.
The time required to fill a package exceeds the time required to produce the bottom of a package.
Because the half-open packaging container must be transferred from the mandrel wheel to the link-belt conveyor, however, the timing of the mandrel wheel and of the link-belt conveyor must agree. This means that, with respect to the goal of ensuring the greatest possible throughput of the filling machine, the time between the stepwise movements of the mandrel wheel is too long, and the time between the stepwise movements of the link-belt conveyor is at the lower limit of the technically feasible time window.